In general, electronic elements are either active or passive elements. Active elements typically include a non-linear feature and passive elements generally never operate non-linearly while operating in their linear region. A typical example of an active element is a semiconductor die such as a transistor, an Integrated Circuit (IC) or a similar device. A typical example of a passive element is a capacitor, a resistor, an inductor or a similar device.
A passive element is usually an external device electrically connected to a semiconductor package and serves to assist the operation the active element (the semiconductor die) by performing a filtering functions or other similar functions. However, when a passive element is mounted on the periphery of a semiconductor package as mentioned above, the area of the circuit is increased and the mounting density of semiconductor packages is greatly lowered.
To reduce the area consumed by passive elements, a structure and method of manufacture for semiconductor packages have been recently proposed in which a passive element is directly mounted on a substrate, which is a structural element of the semiconductor package. The proposed structure will be described below.
A substrate having multiple electrically conductive patterns formed on a top and bottom surface is provided. A semiconductor die is then bonded to the center of the top surface of the substrate. Multiple passive elements are mounted on the electrically conductive patterns located at the periphery of the semiconductor die and bond pads of the semiconductor die are electrically connected to the electrically conductive patterns of the top surface of the substrate by conductive connector (for example, a conductive wire). Also, multiple conductive balls are fused to the electrically conductive patterns of the bottom surface of the substrate. Finally, an encapsulant is applied over the entire top surface of the substrate so that the semiconductor die, the conductive connector and the passive elements are protected from the external environment.
The passive elements can be mounted on the electrically conductive patterns of the top surface of the substrate using SMT (Surface Mount Technology) or THT (Through Hole Technology), which are typically soldered electrical and mechanical connections.
However, the above-described semiconductor package has various disadvantages. First, since the passive elements are mounted on the substrate located at the periphery of the semiconductor die, the area of the substrate must be increased substantially to accommodate the passive elements. Second, to maintain a small substrate area, the passive elements are usually mounted in the vicinity of a singulation line. Therefore, if a substrate warps, passive elements can be damaged by the singulation blade due to relatively small tolerances between a body of the passive element and the singulation line, thus reducing manufacturing yield.
Second, since the passive elements are mounted on the periphery of the substrate, the substrate must be uniquely designed for a particular part due to the configuration of electrically conductive patterns. Further, a cover coat cannot be applied over the passive element locations during manufacture of the substrate, since the passive elements must be subsequently connected.
Third, if a semiconductor die is sensitive to interference, electromagnetic coupling from the passive elements to the semiconductor die is increased in the above-described design, reducing the electrical performance of the die and causing operational errors.
Finally, the semiconductor die is present during both the passive element mounting process and during the semiconductor package mounting process (in which the package including the passive element is mounted in an external device). The above-described process subjects the substrate and the semiconductor die to thermal stress in two different steps, increasing the tendency of the substrate and the semiconductor package to crack.
Therefore, it would be desirable to provide an improved semiconductor package including passive elements and manufacturing method therefor that reduces substrate area, eliminates the risk of damage during singulation, decreases electromagnetic interference between the passive elements and a semiconductor die and subjects the semiconductor die and substrate to less thermal stress during manufacture.